[gson] read / write large file use gson stream

in order to handle with read/write "big" file,
so use gson stream



read

    File jsonInputFile = new File(path);
		FileInputStream fisInput;
		JsonReader reader;
		try {
			fisInput = new FileInputStream(jsonInputFile);
			reader = new JsonReader(new InputStreamReader(fisInput, "UTF-8"));

			ArrayList<Map> categoryALHM = gson.fromJson(reader,
					ArrayList.class);
			
			if(null == categoryALHM || categoryALHM.size() == 0){
				log.info(path+":is null or empty");
				return false;
			}
			reader.close();
			fisInput.close();

		} catch (Exception e) {
			log.info(e.getMessage().toString());
			return false;
		}

write

	 File jsonFile = new File(originalDatpath);
		FileOutputStream fos;
		JsonWriter writer;
		try {
			fos = new FileOutputStream(jsonFile);
			writer = new JsonWriter(new OutputStreamWriter(fos, "UTF-8"));
			writer.setIndent(" ");

			Map getCategoryMap = JsonTool.Json2Map(IbobarDataUtil
					.viewCategory());
			ArrayList<HashMap<String, Object>> getCategoryMapList = (ArrayList) getCategoryMap
					.get("list");

			log.info("original category:" + getCategoryMapList);
			
			gson.toJson(getCategoryMapList, ArrayList.class, writer);
			
			writer.close();
			fos.flush();
			fos.close();

		} catch (Exception e) {
			log.info(e.getMessage().toString());
		}

read and write

	File jsonInputFile = new File(organizeDataPath);
		File jsonOutputFile = new File(usingDatPath);

		FileOutputStream fosOutput;
		FileInputStream fisInput;

		JsonWriter writer;
		JsonReader reader;

		try {
			fosOutput = new FileOutputStream(jsonOutputFile);
			writer = new JsonWriter(new OutputStreamWriter(fosOutput, "UTF-8"));
			writer.setIndent(" ");

			fisInput = new FileInputStream(jsonInputFile);
			reader = new JsonReader(new InputStreamReader(fisInput, "UTF-8"));

			writer.beginObject();
			reader.beginObject();

			while (reader.hasNext()) {
				String key = reader.nextName();

				List<Map> bookOranizeList = gson.fromJson(reader,
						ArrayList.class);
				
				writer.name(key);
				gson.toJson(bookOranizeList, ArrayList.class, writer);
			}

			writer.endObject();
			writer.close();
			fosOutput.flush();
			fosOutput.close();

			reader.endObject();
			reader.close();
			fisInput.close();

		} catch (Exception e) {
			log.info(e.getMessage().toString());
		}